Radiation Damage of F/M and ODS alloys after Fe3+-ion irradiation at 300 C

In this study, Fe3+ self-ion irradiation is used as means of introducing irradiation damage inferritic/martensitic (F/M) steel and oxide dispersion strengthened (ODS) steel. The ion acceleratornamed DuET (at Kyoto University, Japan) was used for irradiation with 6.4 MeV Fe3+ ions at 300 C. The total number of accelerated ions was 2.5 × 1020 ions/m2, and the maximum damage rates inthe F/M and the ODS steels were estimated to be roughly 6 dpa. The irradiation-induced hardnesschange in the damaged layer was evaluated by using nano-indentation. The F/M steel and the ODSsteel commonly exhibited irradiation hardening; however, the irradiation hardening was more activein the F/M steel than in the ODS steel. The microstructure evolutions after the irradiation wereinvestigated; point or line defects were dominantly observed in the F/M steel, while small circularcavities were typically observed in ODS steel.